Self-righting Heli-vehicle: Bounce and Fly

This self-righting probe is designed to travel deep into obstacle-ridden spaces such as caves and rubble-laden buildings to video what it finds.

It is being developed for the Army Research Lab in Aberdeen, Maryland, by Eric Beyer and Mark Costello, a pair of robotics engineers at Georgia Institute of Technology in Atlanta.

The army wants this capability because today's military robots, which run on small tank-style tracks, cannot cope with irregular surfaces and obstacles such as rubble or boulders.

"They usually have trouble and get stuck with even low obstacles and walls a couple of feet high," says Costello. Small helicopters are one alternative, but continuous flying drains the batteries fast.

So their answer - which Costello freely admits is Weeble-inspired - is a rotor-powered, bottom-heavy, self-righting vehicle that spends most of its time on the ground, thus conserving battery power. Instead of flying around, it hops, using a pair of contra-rotating rotors (to avoid the need for a tail rotor) mounted on an aluminium base. All this is encased in a spherical cage made of strong carbon-fibre spars (see diagram).

To steer in flight, the robot swings a weight to tilt in the direction it needs to hop (Journal of Guidance, Control and Dynamics, DOI: 10.2514/1.41331). Whichever way it lands, the weight of the base rights it. Don't take our word for it - Watch the Video!