Aircraft Post-stall Maneuver Control Using Attitude Feedback Linearization

The Nonlinear Dynamic Inversion (NDI) flight control law artificially separates the plant dynamics as the fast and slow loops, which impairs the performance of the aircraft post-stall maneuver. To avoid this problem, a nonlinear flight controller based on the attitude feedback linearization is developed and it controls the angle-of-attack and sideslip angle indirectly through changing the aircraft's attitude. In the controller proposed, the shadow Modified Rodrigues Parameters (MRPs) employed may describe arbitrary maneuver without singularity. The sliding mode control technique is utilized to address the modeling error regarding the aerodynamics and thrust vectoring. The stability of the closed-loop system is analyzed with the input-to-state stability theory. In particular, it is proved that the sliding mode controller, with the boundary layer against the chattering, may asymptotically stabilize the plant in the absence of disturbance, even if the states will not reach the sliding manifold in finite time. Via the Cobra and Herbst maneuver simulations, the proposed controller is compared with the NDI controller and is shown to yield better performance.