Flight Control of a Novel Distributed Tiltrotor UAV With Experiments

ABSTRACT Tiltrotor UAV is a hybrid aircraft that enjoys the advantages of both the conventional fixed‐wing and helicopter in a single platform. The design of a practical and efficient flight control system for this novel aircraft with a complex configuration is still a challenge. This paper proposes a practical fixed‐time control scheme for a novel distributed tiltrotor UAV to improve flight stability. Based on the analysis of the control principle, the dynamic model and control allocation are derived to address the coordinated control problems with redundant actuators. A fast fixed‐time sliding mode attitude controller is subsequently designed to improve the response speed and robustness of the control system. Furthermore, a smooth mode transition strategy is developed to guarantee the stable conversion between fixed‐wing and helicopter modes. Experiments are conducted under different modes to investigate the effectiveness of the proposed flight control scheme.