A Decoupled Approach for Flight Control

Abstract

A decoupling method for flight control is presented that greatly simplifies the controller design. By approximating the higher order derivatives of the angle of attack and sideslip, it enables a rotation controller and a speed controller to be derived independently of each other, and thus gives access to a vast number of controller solutions derived for general classes of rotational and translational systems. For rotational control, a quaternion-based sliding surface controller is derived to align the wind frame in a desired direction, and using standard Lyapunov methods an airspeed controller is derived to ensure that an unmanned aerial vehicle moves with a positive airspeed. Simulations validate the potential of the proposed method, where the unmanned aerial vehicle is able to obtain leveled flight and move in a desired direction with a desired airspeed.

Keywords

• Decoupling
• flight control
• unmanned aerial vehicle
• quaternions
• nonlinear control