To enable a carrier-based unmanned aerial vehicle (UAV) to track the desired glide trajectory and safely land on the deck with the presence of system faults, this paper proposes a neural network-based adaptive sliding mode fault-tolerant control (NASFTC) method. Firstly, the dynamic model of the carrier -based UAV, the actuator fault model, the additional unknown fault model, and the control framework of the automatic carrier landing system (ACLS) were developed. Subsequently, controllers for both longitudinal and lateral channels were designed by using the NASFTC method. The controller consists of three parts: the adaptive laws for compensating the actuator faults, the RBF neural network for compensating the additional unknown faults, and the sliding mode method for ensuring overall trajectory tracking. Then, the Lyapunov function theorem was applied to carry out the stability analysis. Finally, comparative simulations under three different scenarios were conducted. The comparative results show the effectiveness of the proposed NASFTC method, which has fault-tolerant ability and can successfully control the aircraft to execute carrier landing task regardless of the actuator partial loss fault and the additional unknown fault.

The marsupial unmanned aircraft system (UAS) consists of a large parent unmanned aerial vehicle (UAV) and multiple small children UAVs that can be launched and recovered in the air. The employment of marsupial UAS can expand the mission range of small UAVs and enhance the collaborative capabilities of small UAVs. However, the serious aerodynamic interference between the parent UAV and the child UAV will affect the flight safety during the launch and recovery process. In this paper, the interference characteristics of marsupial UAS is investigated through ground tests and CFD simulation. Ground tests compared the lift and power of the child UAV with and without parent UAV interference in different areas, and the simulation extended the experimental scope. Three specific interference regions above the parent UAV are defined, including the area above the rotors, the area above body and the transition area. In the first two aeras, the variation of the disturbed lift is more than 30% of the child UAV weight. In the transition aera, the child UAV will be subjected to significant lift variations and asymmetric moments. According to the interference characteristics of different regions, the safe flight boundaries and the appropriate paths of children UAVs are proposed.

Carrier-based unmanned aerial vehicle (UAV) is prone to faults during missions, leading to abrupt changes in flight dynamic and increasing the difficulty of landing. To address this, this paper proposes a fault-tolerant carrier landing control method with fixed-time convergence and prescribed performance abilities. This method integrates a fault disturbance observer and a prescribed performance controller. The fault disturbance observer estimates and compensates for disturbances caused by faults, enhancing fault tolerance. Meanwhile, the prescribed performance controller ensures that the attitude tracking error remains within predefined bounds despite disturbances, ensuring safe landing. A carrier landing control system based on this method is developed for automatic carrier landing tasks. Numerical simulation tests demonstrate that the proposed control scheme can achieve precise and rapid landing control even with elevator bias and the aileron partial loss faults. Finally, by using a simulated wingtip damage mechanism to induce faults, real flight tests are carried out. The flight tests results demonstrate that the UAV maintains stable attitude and trajectory tracking despite the presence of faults, further verifying the effectiveness and reliability of the proposed method, establishing a foundation for future practical engineering applications.