Carnegie Mellon research have fitted the standard Yamaha 3.5m heli platform (originally designed to fertilize rice paddies) with a custom 3D laser scanner. The result, says New Scientist
, is a UAV that can hug the ground, avoiding obstacles as small as a telephone line:
"The helicopter uses two navigation strategies. First, a long-range planning algorithm uses an existing 3D map to work out a general course that avoids large obstacles like buildings and trees. That map can be preloaded, or built up by the helicopter as it explores a new area.
When the aircraft flies a route, its scanner looks out for other obstacles. As these appear, a local planning system takes over and plots a detour. The UAV can fly between two obstacles with only around 3 metres clearance on each side."