AntBot, a Robot that Moves without GPS

Researchers from the French National Center for Scientific Research (CNRS) successfully developed the first-ever walking robot (called AntBot) that does not rely on the Global Positioning System (GPS).

This newly-developed robot can explore the environment on its own without any GPS or maps. For this invention, the researchers of the CNRS were inspired by desert ants, which are exceptional navigators. Most of the robots that can navigate without human interaction rely on GPS. In case the technology falters, these robots are nothing but a hunk of metal lying around. With the ever-increasing development of legged robots, it is essential to develop a navigational system, which is efficient, reliable, and robust. The navigational technology of AntBot might just be the beginning of that.

AntBot

AntBot is a 3D-printed robot with 6 legs, which allow enhanced mobility even in uneven areas (unlike wheel-based robots). At only 2.3 kilograms, AntBot is significantly lighter and has a highly sensitive camera comprising of only two pixels and two rotating polarized filters. It uses a method similar to path integration (PI) where it observes the rate at which the ground moves across the eye (optic flow). Several models were tested before the researchers were able to make the robot mimic desert ants, efficiently.

No GPS? How does AntBot work?

Desert ants don’t have any GPS to help them travel around in scorching deserts. They use polarized light and ultraviolet (UV) radiation to navigate. Many insects naturally perform similar tasks when foraging. They take meandering paths when visiting their favorite spots before returning directly home in a straight line. Cataglyphis desert ants cover several hundred meters in sunlight and can retrace every step to find their way back to the nest. These ants can measure the rate at which they move relative to the ground, and the eyes can detect polarized light. In order to assess the distance traveled, they use a combination of counting the number of steps taken and observing the motion of objects it passes.

GPS marks your position on the Earth and is accurate up to 4.9 meters at its best. AntBot is equipped with an optical compass and a movement sensor. The latter is used to measure the distance covered and the compass helps keep the robot in the correct direction. That is the information AntBot needs to map out its own routes, explore, and return to where it started. It is accurate to about one centimeter after it covers 14 meters. In essence, AntBot has a built-in “celestial” compass which allows it to reach its target destination accurately.

The Limitations of AntBot

While AntBot’s navigational system is revolutionary, it suffers from certain technical limitations. For instance, AntBot excels in the daytime but starts to become ineffective as nighttime approaches because it doesn’t have the Sun to track its position on the ground. Similarly, the robot can travel to a max distance of about 14 meters and struggles with steep slopes. The positioning system of AntBot overheats after 14 meters thus limiting the distance it can cover. Scientists hope progress will be made soon as there are numerous potential applications for novel robots like AntBot. On the bright side, neither the sky conditions nor the shape and distance of trajectory affected the accuracy significantly. Researchers say AntBot is suited for autonomous navigation in rugged, open-air environments.

What’s in store for the future?

For those interested in building their very own AntBot, the team has put up all the guidelines and downloadable material at https://antbot2u.com/. Researchers believe that a better iteration of this robot (AntBot 2.0?) can be developed, which will be able to travel even further. They hope to improve this technology so that it can be used as a backup in a scenario where GPS navigation fails (a scenario that occurs frequently in busy city areas). Stéphane Viollet of the Aix-Marseille University talked about that and said,

“We are working with a French car manufacturer to try to implement our ‘celestial compass’ on board a [driverless] vehicle. 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.”

The new navigational technologies being developed can be integrated into cars, airplanes, and ships in the near future to lower dependency on GPS. Maybe we should consult the ants again about this matter.