The size of a drone isn’t a trivial matter, and it has a huge effect on the drone’s capabilities and flight characteristics. A large drone is more stable and can carry a higher payload, but requires more powerful motors and larger batteries — a principle that often results in a compounding cycle. Smaller drones are more agile and require less power, but easily become unstable in even mild wind currents. That makes it very difficult to fly small drones outdoors. But new electronic whiskers developed by researchers from the University of Queensland in Brisbane, Australia could help drones detect and respond to minute changes in air pressure.
Animals can use their whiskers to detect both physical contact and the flow of fluid (air or water) around them. A cat, for instance, can determine if it will fit through a tight space based on the contact on its whiskers. A seal can tell if a tasty fish is next to its mouth by sensing the change in fluid flow around its whiskers. That same concept is being applied to small drones with the fabrication of inexpensive whiskers. Each whisker is made from ABS plastic that is melted and then drawn out to form a thin fiber. That is then attached to 3D-printed load plate that is mounted on an array of very sensitive force sensors. If a whisker moves just a tiny bit, it can be detected.
This system is lightweight and cheap to fabricate, making it ideal for small drones. Because the whiskers are so sensitive, they can detect the air pressure change that occurs near a wall. If the drone is moving slowly enough, it can alter its course before a collision. If a collision is unavoidable, it can attempt to reduce the damage by turning off its motors. The electronic whiskers could also be helpful in overcoming wind in order to maintain stable flight outdoors. The whiskers would be able to detect a gust of wind as soon as it starts, and ideally compensate before the wind becomes strong enough to begin pushing the drone into unstable flight.