'Robat' uses sound to map, navigate surroundings

Scientists say they have developed the first fully autonomous bat-like robot that uses sound to move through a novel environment while mapping it.

Bats map new environments while simultaneously navigating through them using echolocation.

The process involves emitting sound and extracting information from the echoes reflected from the surrounding objects, according to the study published in PLOS Computational Biology.

Many theoretical frameworks have been proposed to explain how bats routinely solve one of the most challenging problems in robotics.

However, few attempts have been made to build an actual robot that mimics their abilities.

Researchers from Tel Aviv University in Israel developed the robot, called Robat, that uses a biological bat-like approach, emitting sound and analysing the returning echoes to generate a map of space.

Robat has an ultrasonic speaker that mimics the mouth, producing frequency modulated chirps at a rate typically used by bats, as well as two ultrasonic microphones that mimic ears.

It moved autonomously through a novel outdoor environment and mapped it in real time using only sound, researchers said.

Robat delineates the borders of objects it encounters, and classifies them using an artificial neural network, thus creating a rich, accurate map of its environment while avoiding obstacles.

For example, when reaching a dead end, the robot used its classification abilities to determine whether it was blocked by a wall or by a plant through which it could pass, researchers said.

"To our best knowledge, our Robat is the first fully autonomous bat-like biologically plausible robot that moves through a novel environment while mapping it solely based on echo information," said Itamar Eliakim from Tel Aviv University.

The robot delineates the borders of objects and the free paths between them and recognises their type, Eliakim said.