# Real-Time Safety Decision-Making Method for Multirotor Flight Strategies Based on TOPSIS Model
## 1 Introduction
However, this method uses only language sets or language variables to express expert decision making, ignoring the degree of membership and non-membership of the language variables [23]. Therefore, it is not clear and effective enough to describe the decision value given by experts. [PERSON] et al. [24] proposed the concept of intuitionistic fuzzy sets by combining the concept of intuitionistic fuzzy sets with language sets. Concerning the multi-attribute decision-making method based on intuitionistic language sets, scholars at home and abroad have carried out extensive and in-depth research. [PERSON] et al. [25] proposed the weighted average operator of intuitionistic language, studied its properties, and applied it to the multi-attribute decision-making problem of intuitionistic language. [PERSON] et al. [26] proposed the power mean operator of intuitionistic language sets, which can eliminate the negative impact caused by the extreme evaluation value given by experts, so the decision result is more reasonable. [PERSON] et al. [27] and [PERSON] et al. [28] proposed the Maclaurin symmetric averaging operator and the Bonferroni intuitionistic fuzzy averaging operator, respectively, which can reflect the correlation between numbers of multiple intuitionistic language sets are more suitable for solving practical multi-attribute decision-making problems. [PERSON] et al. [29] proposed a multi-attribute decision-making method based on intuitionistic language preference relations. With the continuous development of fuzzy set theory, some scholars have combined new fuzzy sets with language sets and put forward new fuzzy language sets. For example, with the proposal of the Pythagorean fuzzy set, [PERSON] et al. [30] and [PERSON] et al. [31] combined the Pythagorean fuzzy set and interval-valued Pythagorean fuzzy set, respectively, with a language set and proposed the Pythagorean vague language set and interval-valued Pythagorean vague language set. The properties, algorithms, distance measurement, and information fusion operators of these two types of fuzzy sets were studied, and two new multi-attribute decision-making methods were presented. The fuzzy set theory of [PERSON] [21] is a classical powerful tool to describe uncertain information, which has been widely valued by scholars at home and abroad. After the fuzzy set was put forward, many scholars focused their attention on the research direction of expanding classical fuzzy set theory, in order to improve the ability of classical fuzzy sets in describing uncertain information. Among many extensions, cube sets are a very effective extension form proposed by [PERSON] et al. [32]. [PERSON] et al. [33] extended the classical TOPSIS method to the field of cubic intuitionistic fuzzy sets, proposed the cubic intuitionistic fuzzy TOPSIS method, and applied this method to the supplier selection problem. [PERSON] et al. [34] proposed a cubic intuitionistic fuzzy TOPSIS method based on a non-linear programming model. The fuzzy set uses the interval value and the definite value to describe the uncertain information and is very suitable for expressing the decision-maker's evaluation opinion in the fuzzy environment. The choice of control strategy for a multirotor in flight depends, to a great extent, on the real-time environment and its own state. Therefore, under the framework of a fault classification model, the flight decision-making method of a multirotor based on real-time attribute data was studied. TOPSIS can be used to solve multi-attribute decision-making problems [35]. According to the positive-ideal solution (PIS) and negative-ideal solution (NIS) in the decision-making problem, the distances between the decision object and the ideal and negative-ideal solutions can be judged and sorted according to the degree to which they are close to the optimal solution and far from the worst solution [36]. Therefore, this research proposes a real-time attribute decision-making method for multirotor aircraft based on TOPSIS.