# A Fuzzy Path Selection Strategy for Aircraft Landing on a Carrier
## 5 Conclusions  
The path selection problem for aircraft landing on a carrier is studied in this paper, and a new path selection strategy is developed to solve the problem. The goal is to improve the safety level of aircraft landing and to reduce the workload of the pilot and the LCO at the same time. Firstly, the path selection problem associated with the aircraft landing problem is described. Secondly, essential elements involved in this problem are analyzed. Thirdly, a conceptual model that reflects the essence of solving the problem is developed. \begin{table}
\begin{tabular}{c c c c c} \hline
**Alternative Route** & \(\mathbf{l_{1}}\) & \(\mathbf{l_{2}}\) & \(\mathbf{l_{3}}\) & \(\mathbf{l_{4}}\) \\ \hline Closeness coefficient & [0, 0.51, 5.24] & [0, 0.80, 5.89] & [0, 0.80, 6.41] & [0, 0.20, 2.84] \\ Mean value & 1.57 & 1.87 & 2.00 & 0.81 \\ Rank & & \(l_{3}>l_{2}>l_{1}>l_{4}\) & & \\ The optimal landing path & & \(l_{3}\) & & \\ \hline \end{tabular}
\end{table} 
Table 11: Results of simulation iv. \begin{table}
\begin{tabular}{c c c c c} \hline
**Alternative Route** & \(\mathbf{l_{1}}\) & \(\mathbf{l_{2}}\) & \(\mathbf{l_{3}}\) & \(\mathbf{l_{4}}\) \\ \hline Closeness coefficient & [0, 0.20, 6.47] & [0, 0.21, 6.50] & [0, 0.47, 7.23] & [0, 0.80, 6.79] \\ Mean value & 1.72 & 1.73 & 2.04 & 2.09 \\ Rank & & \(l_{4}>l_{3}>l_{2}>l_{1}\) & & \\ The optimal landing path & & \(l_{4}\) & & \\ \hline \end{tabular}
\end{table} 
Table 10: Results of simulation iii. \begin{table}
\begin{tabular}{c c c c} \hline
**Alternative Route** & \(\mathbf{l_{1}}\) & \(\mathbf{l_{2}}\) & \(\mathbf{l_{3}}\) & \(\mathbf{l_{4}}\) \\ \hline Closeness coefficient & [0, 0.74, 87.00] & [0, 0.80, 88.11] & [0, 0.58, 61.20] & [0, 0.20, 31.48] \\ Mean value & 22.12 & 22.43 & 15.59 & 7.97 \\ Rank & & \(l_{2}>l_{1}>l_{3}>l_{4}\) & & \\ The optimal landing path & & \(l_{2}\) & & \\ \hline \end{tabular}
\end{table} 
Table 9: Results of simulation ii. Using the fuzzy TOPSIS approach improved in this paper, the environmental information, the performance ratings and weights of decision makers are described using linguistic variables. By introducing linguistic variables, the fuzziness in the description of contributing factors and judgment of decision makers can be solved. Subsequently, a mathematical model is built to evaluate the rationality of each alternative landing path under the current environment. To balance the judgements from the LCO and the pilot, the group decision-making approach is introduced, and the optimal landing path is obtained by integrating the decisions of both the LCO and the pilot. Experiments are conducted using the experience-based method by the LCO and the proposed path selection strategy under different environmental settings. Simulation results indicate that the experience-based method is more conservative when making a decision, and the proposed landing path selection strategy can describe the fuzzy environment by marking scores and combining the decisions from the pilot and the LCO. More reasonable decisions can be made by the proposed landing path selection strategy under different environments. The proposed landing selection strategy can reduce the workload of the pilot and the LCO by determining the optimal landing path for the aircraft. This study belongs to one of the key technologies of the automatic landing of carrier aircraft, and it is the first issue to be addressed in the whole process of landing. In the future, the proposed path selection strategy can be applied in flight test simulation, and improvements can be made according to the experimental results. Further, the design of automatic control law will be studied to track the landing path determined in this paper.