Autonomous Flight with Hierarchical Planning

A hierarchical planning method with three levels was demonstrated in simulation and in autonomous flight on a Black Hawk helicopter. The reactive terrain avoidance software has been previously flown and has demonstrated the ability to sense and avoid previously unknown terrain while autonomously guiding the aircraft to a destination. The new mission level software adds the ability to make mission-length plans based on a stored terrain map while minimizing mission risk. Pilot or operator input can be as minimal as simply entering a destination and waiting, but the pilot or operator also has the capability to replan while enroute, change speed, and add direction bias to influence the flight path. The system was flight tested at four different sites with different types of terrain. The addition of this mission level improves the ability of the system to keep to a desired height above ground level, while allowing the pilot or operator to better predict the route of the aircraft and time to destination.