Nonlinear Dynamic Inversion of a Flexible Aircraft

This paper investigates the use of dynamic inversion for the attitude control of a flexible aircraft. Input-output feedback linearization-based dynamic inversion is used to linearize the angular velocity and forward translational velocity equations of motion. A proportional-integral-derivative (PID) controller based on the direction cosine matrix (DCM) that describes the attitude of the aircraft is used, in addition to a proportional-integral (PI) controller to maintain a desired airspeed. Numerical simulations are performed using the proposed dynamic inversion controller, as well as more practical implementations of the controller that include saturated control inputs and no knowledge of the aircraft's flexible states. In simulation, the practical controllers successfully stabilize a flexible aircraft with reasonable control surface deflections.