What are “Human rescue” drones and how they work

The advancement of technology could be defined by many as the revolution that seems to have no end. More and more scientific discoveries allow technology to grow and displace, in a matter of months or a few years, what was once considered “the latest advance”.

This is the case year after year with smartphone, cameras, computers and even drones; being this last device in which this article will focus, because now they have found a new use for this incredible technology: the rescue of people by means of the voice.

For some years now, researchers from the Fraunhofer Institute for Communication, Information Processing and Ergonomics in Germany (Fraunhofer FKIE) have focused their efforts on planning, creating and controlling gifts that “hunt” people who are trapped in a emergency situation and that they need to be found in order to help them.

To achieve this, the drone uses a series of microphones that allow it to recognize people’s screams and thus locate them much faster than a human rescue party would.

For this, scientists have developed a beamforming system (a path router to improve information access), with which the microphones can detect clean sounds and focus their course in the one whose direction is more focused on the target.

“Ideally, to use beamforming techniques, it is practical to use an array of identical microphones that deliver synchronous data. We opted for a very particular array called Crow’s Nest, where all the microphones are randomly placed on a sphere. This type of matrix provides sound coverage in all directions and is equally good at all of them,” explained the Fraunhofer FKIE researcher, Macarena Varela, in conversation with the specialized portal Mashable.

Currently, each of the drones has a total of 32 microphones in its design, and although it might be thought that the best thing for the project is to place fewer of these artifacts that have greater reach force, for the researchers it seems that in this case “more is better”.

“Since MEMS (microelectromechanical system) microphones are so small and affordable, we are planning to double the number of microphones in the near future instead of reducing them,” indicated Varela.

The devices have 32 microphones in their matrix, in order to locate people easier.

According to scientists, the ideal is to have a greater number of microphones that allow to improve the precision of the angle of the captured sounds and in this way make the drone more accurate when determining the location of a person.

In short, this system works like the resolution on a screen: The more pixels, the better the definition of an image, although in the case of drones the precision of the sound will be better.

“The data from all the microphones are combined, after adding delays or phases, to achieve maximum sensitivity for a selected direction, and thus form a sensitivity beam. Then, by varying or scanning the direction, the search for sound sources is achieved.” Added the researcher.

Finally, Macarena Varela assured that in recent months they have been working on how to more effectively filter the different sounds of the environment, in order to reduce the noises present around the drone, while impulsive sounds from people are recognized “Like tapping, clapping and screaming.”

“In previous tests in the laboratory, we were able to detect impulsive sounds, such as applause, presence of rotor noises. We are currently processing the data with the drone flying”

“However, we also face new challenges, such as drone noise while flying,” Varela said, adding that “in other words, we have the experience in our team, so it is a matter of time before this system can be deployed on a large scale to search and rescue teams around the world.”