LAUSR

This paper investigates the disturbance utilization-based attitude control for the fixed-wing unmanned aerial vehicle (UAV). The disturbance utilization condition (DUC) is formed based on the Lyapunov function analysis to retain the disturbance that benefits the stability of closed-loop systems. To reduce the sign-misjudgment of disturbance coupling terms induced by the DUC, the disturbance estimation error analysis auxiliary system (DEEAAS) is designed based on the disturbance observer (DO). Combined with the DEEAAS and the DO, the boundaries of the disturbance estimation error (DEE) are derived. Subsequently, the composite DUC is proposed based on the above boundaries and the given thresholds to replace the basic DUC. Then, the boundedness of the attitude tracking errors of the fixed-wing UAV can be ensured by the controller designed with the composite DUC. And combined with the derived boundaries of the DEE and the given thresholds, the adaptive DO and the adaptive DEEAAS are also designed to avoid the use of big parameters. In addition, sufficient conditions that stabilize the attitude closed-loop system of fixed-wing UAVs equipped with the disturbance utilization-based controller (DUBC) are given. Finally, the numerical simulation for the fixed-wing UAV illustrates the effectiveness of the proposed DUBC.