Dexterous uavs for precision low-altitude flight

Abstract

Low-altitude flight usually introduces ground-effect disturbances and other backwash issues. In the new field of aerial mobile manipulation, it often includes close operations to structures for either inspection or manipulation of the structures. Although there has been a fair amount of research work of free-flying satellites with graspers, the more recent trend has been to outfit UAVs with graspers to assist various manipulation tasks. While this recent work has yielded impressive results, it is hampered by a lack of appropriate test beds for aerial mobile manipulation, similar to the state of ground-based mobile manipulation a decade ago. Typical helicopters or quadrotors cannot instantaneously resist or apply an arbitrary force in the plane perpendicular to the rotor axis, which makes them inadequate for complex mobile manipulation tasks. Based on the concept of force closure (a term from the dexterous manipulation community), this chapter introduces a new type of dexterous, 6-DOF UAV which provides the unique capability of being able to resist any applied wrench, or generalized force/torque, providing more precise control during low-altitude flight.