High performance maneuver control for autonomous flight vehicles

1996 by the American Institute of Aeronautics and Astronautics, Inc. All rights reserved. A fully autonomous flight vehicle must be capable of accurately tracking a desired trajectory for the safe and effective completion of a given mission. This paper presents an approach to robust maneuver autopilot design based on a six-degree-of-freedom nonlinear trimming algorithm coupled with a robust tracking controller. Acceleration commands required for closed-loop tracking of a desired trajectory in an Earth-fixed reference frame are provided by a simple guidance strategy. The trimming algorithm generates optimal state commands and feed-forward controls to accomplish the maneuver, while assuring that these commands can be tracked by an inner-loop controller without violating vehicle performance or actuator constraints. This approach is demonstrated in simulated flight of an actual remotely piloted vehicle, named Ariel, that has been developed at the University of Sydney. Excellent tracking performance is achieved for a representative threedimensional trajectory using a high-fidelity aircraft model with nonlinear dynamics and realistic wind gust disturbances. In addition, an analysis of system robustness to uncertainty in the vehicle model is performed.

High performance maneuver control for autonomous flight vehicles Conference Paper