Autonomous Operation of Hovering/Staring Fixed Wing Unmanned Aerial Vehicle

DARPA has long demonstrated interest in hovering and perching aircraft for staring surveillance by funding research on many types of rotorcraft, from conventional helicopters to ducted fans like the OAV. Recently, hovering has become commonplace with hobbyist's amazingly agile fixed wing '3-D' aircraft. Though the bandwidth requirements are low, precision hovering is not a trivial task, requiring simultaneous coordination of up to 4 control inputs. Also, tail sitting is possible only with high power loading and low disk loading. Most 3-D planes are very light, but when a useful payload is added (autonomous avionics, video camera and transmitter, large batteries etc.), this becomes more dicey. We propose a Phase 1 demonstration of fixed wing autonomous hovering using a modified version of our 18" Locust MAV. Our avionics, including GPS/INS, video and data transceivers, weigh less than 2 oz. Planned changes are 1) a large, variable pitch optimized tractor propeller 2) a sonic altimeter for perching 3) customization of the autopilot algorithms to include a hover mode. The control topology is unchanged, but the aerodynamic derivatives are obviously altered by the static, hovering condition. This isn't of great concern as Locust regularly flies in an aerodynamically unstable loading condition.