Nonlinear Control of a Fully-Actuated UAV

Abstract

Fully actuated UAVs provide enhanced maneuverability and accurate six-degree-of-freedom (6-DoF) control, making them well-suited for demanding tasks such as aerial manipulation, operation in confined environments, and fault-tolerant missions. However, the resulting over-actuation poses challenges in control allocation and robustness to external disturbances. This paper develops a sliding-mode control strategy integrated with a control-allocation framework to achieve precise maneuvering of fully actuated UAVs. The approach is demonstrated on a quadrotor equipped with dual-axis tilting propellers. The proposed guidance framework leverages the vehicle’s full actuation to enable a decoupled design for translational and rotational dynamics. Under the assumption of symmetric actuation across all rotors, thrust vectors are systematically constructed to meet the prescribed tracking objectives. These vectors are then employed in an inverse control-allocation problem to compute the required thrust magnitudes, along with the associated servo and tilt angles for each rotor. Extensive simulations are presented to validate the performance of the proposed scheme across a variety of dynamic reference trajectories.