# Fault-Tolerant Control for Carrier-Based Aircraft Based on Adaptive Fuzzy Sliding-Mode Method
## 7 Conclusions  
To realise accurate and safe landing of CBA under actuator faults, an autonomous landing control system was designed in this study based on AFSMFTC. In the system, the guidance subsystem comprising the longitudinal channel controlled by a path controller using a \(\sigma-\beta\) filter and the lateral channel controlled by the PID method was designed to transform position errors into angular commands. APCS was designed to keep the velocity constant, and AFSMFTC, comprising an adaptive fuzzy network, adaptive laws and a sliding-mode controller, was designed to complete tracking and control for the attitude angle and fault compensation. The adaptive fuzzy network was shown to be effective at weakening the impacts of unknown disturbances on the control system through fuzzy approximation for the sliding-mode switching terms without estimating the upper limit of perturbation. The adaptive laws are used to counter the actuator efficiency loss fault, automatically adjust the controller parameters according to any fault condition and complete FTC under fault conditions, and the sliding-mode controller is used to ensure CBA tracking along the expected path. Furthermore, the Lyapunov function was used to theoretically analyse the disturbance compensation and FTC of the CBA, respectively, and it demonstrated uniform boundedness in the tracking errors of the closed-loop system. Finally, to verify the applicability of the AFSMFTC method, three different landing scenarios were simulated and compared. The simulation results showed that when the control system experiences actuator faults and unknown disturbances, the proposed AFSMFTC method is effective at countering them. Consequently, the landing accuracy and performance of the CBA are greatly improved compared to those with conventional control.  
The fault-tolerant landing control technology for CBA is a challenging subject. This study specifically focuses on the research of fault-tolerant control technology under actuator efficiency loss fault. In future studies, it would be beneficial to investigate different types of faults in various scenarios. Additionally, it is crucial to consider the impact of sensor measurement errors on the landing control system of CBA. Researchers can pay attention to sensor accuracy, calibration methods, and the influence of environmental disturbances, while developing corresponding algorithms and techniques for filtering, calibrating, and detecting redundancies in sensor data. These efforts will enhance the robustness and reliability of the landing control system, ensuring safe and stable landings for carrier-based aircraft under various operating conditions.  
Conceptualization, Z.X. and J.A.; methodology, Z.X.; software, Z.X.; validation, Z.X.; formal analysis, Z.X.; investigation, Z.X.; resources, J.A.; writing--original draft preparation, Z.X.; writing--review and editing, Z.X.; visualization, Z.X. All authors have read and agreed to the published version of the manuscript.  
This study was supported in part by the Shanghai Natural Science Fund under Grant No. 22 ZR1404500.  
Not applicable.  
The data presented in this study are available on request from the corresponding author. The data are not publicly available due to the involvement of sensitive information about carrier-based aircraft in this research data.  
The authors declare no conflict of interest.