Robust feedback linearization approach to autopilot design

The feasibility of autopilot design for highly maneuverable bank-to-turn (BTT) missiles using feedback-linearization-based approaches is investigated. Two schemes, namely, feedback linearization and robust feedback linearization, are designed and compared based on a full-scale six-degree-of-freedom HAVE DASH II terminal homing missile model. Although the feedback linearization controller is quite satisfactory in general, a sizable coupling between the longitudinal motion and lateral motion for large maneuvers is observed. This is attributed to the uncertainties arising from the approximation of the aerocoefficients and model simplification. The second scheme, which adds a robust outer-loop design based on Lyapunov´s second method to the first scheme in order to account for this uncertainty, shows a significant improvement over the first scheme