Ant-inspired roving robot eschews GPS
Ordinarily, when we hear about robots or other devices that are able to independently navigate outdoors, it's a given that they use GPS. French scientists have developed an alternative, however, in the form of a six-legged robot that navigates like an ant.
Known appropriately enough as AntBot, the machine was developed by researchers from the CNRS institute and Aix-Marseille University. Its navigation system is based on that of the Cataglyphis desert ant, which can travel up to several hundred meters from its colony without getting lost.
Most foraging ants are able to find their way back to their colony by following a pheromone trail, which they deposit on the ground as they head out in search of food. In Cataglyphis' desert habitat, though, the hot sunlight would quickly burn those pheromones away. Instead, the ant orients itself in two ways.
First, it determines its heading by noting its position relative to patterns of polarized light in the sky – these are visible to the ant's eyes regardless of whether it's sunny or overcast. Secondly, it determines how far it's travelled by counting its steps, and through optic flow – the latter refers simply to a process in which an observer visually notes how quickly they pass by surfaces and objects in their environment.
AntBot incorporates its own version of this two-pronged approach.
It's equipped with an optical compass, which it uses to check its heading based on the polarized light in the sky, along with an optical movement sensor, which it uses to visually determine how far it's walked from its starting point. The setup has allowed the robot to explore its surroundings up to a total distance of 14 meters (46 ft), finding its way back to its base with a precision of up to 1 cm (0.4 in).
It is now hoped that descendants of the 2.3-kg (5-lb) AntBot could someday be used to autonomously traverse rough terrain such as that of disaster sites, in situations where GPS is unavailable or impractical.
A paper on the project was recently published in the journal Science Robotics. And if you want to see AntBot scurrying about, you can do so in the French-language video below.