Most flying robots, but not all, are small, so they can access hard-to-reach places. Some designed to emulate insects can be as tiny as real insects. Most flying robots use a helicopter-style design (three to 12 or more rotors) or emulate the movements of birds. Some bird-like designs glide. Others incorporate the much more difficult-to-achieve locomotion of flapping.
Flying robots can serve a wide variety of purposes. Many work in swarms, cooperating with one another to accomplish their tasks. Surveillance, reconnaissance, and search and rescue in military and first responder situations are popular applications for aerial robots.
Yet not all these robots are considered unmanned aerial vehicles. Some have been used to assemble architectural structures or perform agricultural duties such as crop dusting or pollination. Many are autonomous. Some are remote-controlled, and some are autonomous robots with real-time communication from remote pilots.
Click the image below for a slideshow of examples of these robots.
The Nano Air Vehicle, a DARPA-funded hummingbird-like demonstrator robot made by AeroVironment, flaps its wings to fly in any direction. The remote-controlled Nano can hover with precision like the real bird, and it can fly clockwise and counterclockwise. It weighs 19gm (0.67oz), including batteries, video camera, motors, and communications systems, and it has a wingspan of 16cm (6.3 inches). Its size and weight are within the range of real hummingbirds, and, like them, it uses its wings for control and propulsion. The Nano can hover continuously on its own power source for eight minutes. It can shift from hovering to a forward flight speed of 17.7kph (11mph). While hovering, the Nano can tolerate side wind gusts of up to 8kph (5mph)
without losing more than 1m (3.28 feet) of altitude.