Nonlinear Non-minimum Phase Flight Vehicle Control Using Dynamic Sliding Manifold

Design and synthesis of a nonlinear non-minimum phase supersonic flight vehicle longitudinal dynamics control for g commands output tracking are presented. The non-minimum nature of the resulting input/output pair necessitates using a modified switching manifold in sliding mode control theory. Dynamic sliding manifold is designed to compensate for unstable internal dynamics of the system associated with the coupling between the moment generating actuators and the aerodynamic forces on the flight vehicle. The employed method is simple to implement in practical applications and enables the sliding mode control design to exhibit the desired dynamic properties during the entire output-tracking process independent of matched perturbations and accommodates to unmatched perturbations. Results of simulations are presented to demonstrate the performance, robustness, and stability of the considered autopilot.