The First Walking Robot that Moves Without GPS

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Inspired by the ant desert known for being an extraordinary solo sailor, researchers from the CNRS and Aix-Marseille University, at the Institute of Movement Sciences - Étienne Jules Marey (ISM), designed the first robot to legs able to move without GPS: AntBot can explore its environment randomly and go home automatically, without GPS or mapping. His secret: a celestial compass sensitive to polarized light from the sky. This work, published on February 13, 2019 in Science Robotics , makes it possible to imagine new navigation strategies for the autonomous vehicle and the robotics of tomorrow.

Our eyes are insensitive to polarized light and ultraviolet radiation, but this is not the case with the ants that use them to find their way into space. The desert ant Cataglyphis, in particular, is able to walk several hundred meters in the desert in the middle of the day to find food, then to return in a straight line to its nest, without getting lost. Impossible for her to use pheromones: she goes out at a time when the temperature would burn any drop. Her extraordinary talent as a navigator is based on two pieces of information: the measured heading thanks to a sort of "solar compass", which allows her to orient herself using the polarized light of the sky, and the distance traveled, measured by simply counting her steps and by integrating the velocity of movement with respect to the ground measured optically by his eye. Distance and heading are two important pieces of information that, when combined, allow him to return safely to the nest.

AntBot, the brand new robot designed by researchers CNRS and Aix-Marseille University (AMU) at the ISM, reproduces the exceptional navigation capabilities of the desert ant. It is equipped with an optical compass to determine its course through polarized light, and an optical scroll sensor directed to the ground to measure its distance traveled. Armed with this information, AntBot has proved capable, like the desert ant, of exploring its environment and returning by its own means to its base, with a precision of up to 1 cm after having traveled a total distance of 14 meters. Weighing only 2.3 kg, this robot has six legs which gives it increased mobility, allowing it to move in complex environments.

The optical compass 1developed by scientists is sensitive to the polarized ultraviolet rays of the sky. Thanks to this "celestial compass", AntBot measures its course with an accuracy of 0.4 ° in clear or cloudy weather. The precision of navigation achieved with minimalist sensors proves the innovative capacity of bio-inspired robotics which allows here to kill three birds with one stone: to bring new knowledge on the navigation of the ant of the desert, by testing thanks to AntBot several models designed by biologists to mimic this animal, develop a novel robot, and design new innovative and unconventional optical sensors. Before potential applications in aerial robotics or the automotive industry for example, now remains to break new ground,