Drones can echolocate like bats with a speaker and quartet of mics

Scientists have devised a new method to allow drones to navigate their surroundings by taking inspiration from bats. Researchers have found that drones can echolocate within their surroundings using four microphones and a speaker with the help of some algebra and geometry. Researchers on the team say that the work also has potential uses in underwater vehicles and cars.

Researchers have been able to use their techniques to reconstruct the wall configuration of rooms by using echoes picked up by microphones on the drone. When one of the mics hears an echo, the time difference between the moment the sound was produced and when it was recorded is measured. The time difference shows how far the sound traveled after bouncing off a wall.

The big challenge for the team is in determining which distance corresponds to which wall, a process called echosorting. By sorting the echoes accurately, the drone can determine that all walls that are heard are there. This prevents the algorithm from creating a ghost wall. The team is directing their research at a pair of issues in engineering – localization and mapping.

The team has shown that it is possible for a minimal setup of four microphones arranged in a non-planar shape along with a loudspeaker for emitting one signal to reconstruct a room is possible. The next step of the tame is to look at other scenarios like when drone movement is restricted or when the drone listens to echoes of consecutive sounds when it is moving.

The team says the research could be applied in several ways. One is as a device carried by a person, attached to a car, or used underwater. Having more signal input could also prevent the system from relying on one type of input. That would improve the chances that objects could be detected more accurately and in a wider variety of conditions.