A team of researchers was inspired by the ability of a mosquito to fly and land in the dark to develop a new sensory system to prevent collisions, which was tested on a quadcopter drone.
Led by Richard Bomphrey, scientists at the Royal Veterinary College (RVC) in London, analyzed in detail the sensory mechanism of the Culex quinquefasciatus mosquito and found a way to mimic the insect's ability to use airflow to detect (and avoid) obstacles .
Even in the dark, mosquitoes are able to land very lightly. This feat is due to mechanical detection, a response to mechanical stimuli that allows these insects to feel obstacles without seeing them. Unlike bats, which sail thanks to a biological sonar system, mosquitoes use a combination of wings, antennae and airflow.
These insects fly by flapping their elongated wings very quickly, producing jets of air that provide support. If these jets encounter an obstacle, airflow patterns change shape and can be detected by a variety of receivers at the base of the mosquito's antennae, called the Johnston's organ.
In this way, the mosquito is able to build an image of the environment around it through “aerodynamic images”, allowing to map the soil and other obstacles.
After analyzing the mosquito's flight through dynamics simulations, the scientists came to the conclusion that Johnston's organ is ideally located to measure changes in the pattern: as it is located in the antennas, this set of receivers detects changes in air flow with very easy at low altitude, with the response decreasing at higher altitudes.
The researchers found that the biggest differences in airflow patterns occur above the head, meaning that the insect's antennae are ideally positioned to sense these changes, despite being further away from the ground.
The team used their findings to develop a miniature quadcopter drone, fitting it to a biological-inspired sensor device. The device consisted of a series of probe tubes connected to differential pressure sensors.
Then, by measuring the speeds of airflow around the quadcopter, the scientists identified the ideal place to place the probes in order to obtain maximum sensitivity.
According to the New Atlas, the quadcopter was able to detect surfaces at a sufficient distance to avoid the ground or walls, with little or no data processing. The new system is still considered lightweight, energy efficient and scalable.
The researchers believe that this surface detection capability can be extended to helicopters, making them safer when flying in tricky, low-visibility conditions. The scientific article with the results was published in Science.