A new visual system will tweak pilotless aircraft's ability to navigate even more accurately by imitating how insects do it.

"UAVs (pilotless aircraft) are used in crop dusting, bushfire monitoring, tracking algal blooms or crop growth and infrastructure inspection as well as defence roles," says Richard Moore, researcher at the Vision Centre and the Queensland Brain Institute.

"Some of these tasks require the aircraft to fly close to the ground and amongst obstacles, so it is crucial that the aircraft knows its heading direction and roll and pitch angles accurately," adds Moore, according to a Queensland institute statement.

But all of them suffer from problems such as noise-induced drift, and can be adversely affected by the motions of the aircraft or materials in the environment surrounding the sensors, he explains.

"This means that UAVs can't perform significant manoeuvres without losing their sense of direction for a while," Moore points out.

Accordingly, researchers have designed a vision-based system that provides aircraft with the same advantage that insects have - a fixed image of the sky and the horizon.

"If you watch a flying insect, you will see that their heads are upright when they turn their bodies," Moore says. "Keeping their heads still allows them to have a stabilised image of the horizon and the sky which is crucial in determining their heading."

"With the new system, we only have to tell the aircraft that it's in the upright position when it starts flying. It will then use that as a starting point to work out which is sky and which is ground, and train itself to recognise the differences.

"The ability to estimate the precise roll and pitch angles and the heading direction instantaneously is crucial for UAVs, as small errors can lead to misalignments and crashes," he adds.