Three-dimensional reactive navigation will be an essential component of low-altitude unmanned rotorcraft operations in urban environments. Successful navigation will require that the rotorcraft sense the surrounding obstacles, incorporate these data into its world model, and react to new obstacles to ensure both vehicle survivability and satisfactory completion of all mission objectives. These tasks must all be done with possibly large uncertainties in vehicle and obstacle position measurments, and with winds and turbulence. This paper presents one possible solution built on heuristic planning concepts which utilize existing capabilities in two-dimensional route planning. A repetitive planning process and a multi-plane route planner are used to produce 3D navigation trajectories that satisfy navigational and mission-level constraints. Simulation evaluation and flight test validation results are presented.

This paper is located in the AHS International 63rd Annual Forum (TL716 .A1 A512 2007 VOL.1).