Flies’ brains can detect threatening drones
Bio-inspired design has been a hallmark of technological progress, and it’s still true in the age of flying robots. The latest evidence comes from Australia, where researchers have mapped the visual systems of hovering insects as a way to detect acoustic signatures of drones up to 2.5 miles away.
Anthony Finn, professor of autonomous systems at the University of South Australia, says insect vision systems have been mapped for some time to improve camera detections. But applying the same method to acoustic data represents a major innovation.
“Biovision processing has been shown to significantly increase the detection range of drones in both visual and infrared data. However, we have now shown that we can pick up crisp, clear acoustic signatures from drones, including very small and silent, using an algorithm based on the visual system of hovering,” says Finn.
Potential research applications, of course, include military and defense uses. In addition to the University of South Australia and Flinders University, defense firm Midspar Systems has participated in trials using bio-inspired signal processing techniques. Such techniques, according to the researchers, have a detection rate up to 50% higher than that of existing methods.
The hover, which can hover over plants to collect nectar, was chosen because of its superior visual and tracking capabilities. Darkly lit regions are visually very noisy, but insects like the hoverfly can process and capture visual cues with remarkable efficiency. Mapping this same processing technique to acoustic detection has resulted in a substantial increase in detection capabilities, including in noisy environments.
“Unlicensed drones pose particular threats to airports, individuals and military bases,” Finn says. “It is therefore becoming increasingly critical for us to be able to detect specific locations of drones at long distances, using techniques that can pick up even the weakest signals. Our trials using the hover-based algorithms show that we now we can do it.”
The researchers specifically looked for patterns (narrowband) and/or general signals (wideband) to pick up drone acoustics at short to medium distances. The new bio-inspired treatment technique improved detection ranges by 30-49%.
The findings were reported in The Journal of the Acoustical Society of America.